Fatto generale: 17715 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 17715 is an uninteresting number.
Trivia: 17715 is an uninteresting number.
Data storica: July 1st is the day in 69 that Tiberius Julius Alexander orders his Roman legions in Alexandria to swear allegiance to Vespasian as Emperor.